PTGS2 and cholangiocarcinoma: This strategy is currently being tested in several preclinical and clinical trials in other tumors, such as tivantinib in HCC [129], cabozantinib in advanced thyroid cancer [130], and COX-2 inhibitors such as celecoxib, which inhibits the proliferation of CCA cells in vitro [131] and reduces tumor growth in rats with chemically induced CCA [132].